This invention relates to a drilling or milling head with a collet chuck operated by a quick-change mechanism and a drive shaft connected to a motor, the collet chuck being opened by axial displacement with respect to a clamping sleeve and the force necessary therefor being transferred through a friction clutch, and having a transmission for driving the collet chuck. In particular, this drill or milling head is suitable for machines which serve for the production of fine structures such as circuit-board milling machines and engraving machines.
In the as yet unpublished patent application Ser. No. 197 48 735.1 a drilling or milling head of this kind is described. In this drilling or milling head a drive shaft of the motor is connected by a coupling to a drive shaft of the collet chuck. Thus, the rotatory speed of the chucked tool is always equal to the motor speed.